Protein tyrosine kinase 7 (PTK7), also known as colon carcinoma kinase 4 (CCK4), is a receptor tyrosine kinase originally cloned from normal human melanocytes and separately from colon carcinoma tissue. High levels of PTK7 have been identified in a number of tumor cells, including bladder, breast, colorectal, kidney, and lung cancers and melanoma. PTK7 expression has also been observed on adult myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) cells.
The treatment of cancer has improved over the past decade with surgery, radiation therapy, and chemotherapy as the primary treatment options. Such treatments can extend survival and/or relieve symptoms in many patients but are not likely to produce a cure for many patients. Consequently, there remains a significant need for additional therapeutic options for cancers.
To this end, the present invention provides novel antibody-drug conjugates that target PTK7-positive cancers. The disclosed anti-PTK7 antibody-drug conjugates can exert a clinically useful cytotoxic effect on PTK7 expressing tumor cells without exerting undesirable effects on non-PTK7 expressing cells.